1. Field of the Invention
This invention relates to a device which is expandable to engage the interior of a tube in which the device is located. The device, when expanded, may form a mechanical interference fit with the tube, in which case it can function as an anchor. Alternatively or additionally the device may form a seal with the interior of the tube. To this end, the device may include an elastomeric member or coating to engage the interior of the tube. If the device, when expanded, forms a seal with the interior of the tube, it may function as a packer. If it forms both a mechanical interference fit and a seal it may serve as a packer anchor. The device of the present invention has particular application in the oil and gas industry where it may be used as an anchor, a packer or a packer anchor (according to its configuration) inside tubing located in an oil or gas well. It is to be understood, however, that the invention is not limited to such applications and embodiments of the present invention may be applicable to a wide range of circumstances where it is necessary either to form a mechanical interference fit with the interior tube and/or to form a seal with the interior tube.
2. The Prior Art
Anchors, packers and packer anchors are well known within the oil and gas industry. A design of packer anchor which has the advantage of a particularly thin-walled configuration is described in our co-pending United Kingdom patent application 0417765.5, the contents of which are incorporated herein by reference. The packer anchors described in that application each comprise an outer tubular member which is expandable into engagement with the interior of a tube in which the member is located, and a swage which is forced into the outer tubular member during setting in order to expand the outer tubular member as required. The present invention is concerned with improvements in the design of such swage-actuated anchors, packers or packer anchors.